| 20 | = | 549 1000 | ( | 115 | − | x | ) |
| 方程右边 = | 549 1000 | × | 115 | − | 549 1000 | x |
| = | 12627 200 | − | 549 1000 | x |
| 20 | = | 12627 200 | − | 549 1000 | x |
549 1000 | x | = | 12627 200 | − | 20 |
549 1000 | x | = | 8627 200 |
| x | = | 8627 200 | ÷ | 549 1000 |
| = | 8627 200 | × | 1000 549 |
| = | 8627 | × | 5 549 |
| x | = | 43135 549 |
| x | = | 78.570128 |